Lined frozen food boxes



March 19, 1957 Filed Dec. 4, 1953 R. C. STENGER LINED FROZEN FOOD BOXES4 Sheets-Sheet l INVENTOR. Richard C. Sfenyer BY V M1. ATTORNEY March19, 1957 R. c. STENGER LINED FROZEN FOOD BOXES Filed D80. 4, 1953 4Sheets-Sheet 2 INVENTOR. R/c/zaro C. Sfenger WAW A TTORNEY March 19,1957 R. c. STENGER 2,785,845

LINED FROZEN FOOD BOXES Filed Dec. 4, 1953 4 Sheets-Sheet 3 IN VEN TOR.Richard C Sfenyer R. C. STENGER LINED FROZEN FOOD BOXES March 19, 1957 4Sheets-Sheet 4 Filed Dec. 4, 1953 INVENTOR. Richard C. Sfenger BY M6. W

l ATTORNEY United States Patent LINED FROZEN FOOD BGXES Richard C.Stenger, San Carlos, Caiii, assignor to Baljak Corporation, Wilmington,Del a corporation of Delaware Application December 4, 1953, Serial No.396,123

5 Claims. (Cl. 22935) This invention relates to improvements in cartons,trays, or other structures made from blanks of cardboard,

paperboard, or other suitable foldable sheet material, hereinaftercollectively referred to as boxes or folding boxes.

of the box machinery required for setting up the boxes and because ofthe rapidity with which flat .box blanks can ibeassembled into box formready for filling.

The assembly of glueless box corners which are designed to bemechanically tight in the sense that they form a rigid corner equallyresistant to forces acting from the inside of the box outwardly and fromthe outside of the box inwardly, generally requires an assemblymechanism including a plunger on which movable elements are mounted.These elements press against the inside of the box walls which comprisethe locking cuts for the purpose of opening the cuts sufficiently topermit the lock fiaps to enter freely. Thereafter the movable elementsgrasp a portion of the lock flaps and positively pull them into engagingposition whereby failure of locking is eliminated.

The frozen food industry requires boxes which must be capable of holdinga certain amount of fiuid contents without leakage from the time offilling to the time of freezing. Fluid tightness is a primaryconsideration and is generally achieved by the use of a liner. Since theliner overlies the interior surface of the blank, it does not permit ofthe use of projecting and retracting elements on the plunger vwhichbearagainst the inside of the box walls and flex wall portions outwardly forthe purpose of opening cuts and then pulling the locking portion of theflaps into engaging position.

in order to overcome the assembly limitations imposed by the liner, ithas been suggested to modify the box structure and its assembly bymoving the box walls not only into upright position with respect to thebox bottom,

but farther towards the inside of the box through an angle of more than96 degrees. This initial motion is then followed by a locking motion inthe reverse direction until certain hook-type locks are engaged whichmake the corners movement tight only in the sense that the cornersresist pressure directed from the inside to the outside. in order topermit the aforementioned first movement, the edges of the side wallsadjacent box corners must be trimmed back to an angle less than 90degrees. Thus shaped, the walls are not available as reinforcingstructures to prevent movement of the adjacent erected box walls towardsthe inside in response to force acting from the outside.

It is most desirable to provide for an end-to-panel engagement betweenthe walls containing the locking cut and the wall to which the lock flapis articulated, since this ice engagement stifiens the box corneragainst forces acting from the outside to the inside, and it is furtherdesirable to provide for movable locking elements on assembly mechanismfor positively pulling the locking edges into positive engagement.

The present invention provides a box corner construction and a. boxblank for forming not only a liquid-tight box corner, but also a cornerconstruction which is movement-tight in the sense that it resists forcesacting from the outside of the box towards the inside as well as forcesacting from the inside of the box towards the outside.

The box corner construction according to the invention also includescorner flaps which engage and guide the liner during assembly to formneat gusset folds at the box corners.

The assembly of the box blank incorporating the invention requires aminimum of time, since the box walls need only be folded into uprightposition, by one controlled motion, in distinction from assemblyprocedure requiring two controlled motions, namely, one in which the boxwalls are moved through an angle of more than .degrees and a secondcontrolled motion returning the box walls to the upright position.

These and various other features, objects and.advantages of theinvention will appear more fully from the detailed description whichfollows, accompanied by drawings showing, for the purpose ofillustration, a preferred embodiment of the invention. The inventionalso consists in new and improved details .of construction hereinafterset forth and claimed.

Although the characteristic features of the invention which are believedto'be novel will be particularly pointed out in the claims appendedhereto,.the invention itself and the manner in which it may be carriedout, may bebetter understood by referring to the following descriptiontaken in connection with the accompanying drawings forming a part of-itin which:

Fig. l is a plan viewof a fiat lined box blank embodying the invention,the inside surface of the blank, and the liner facing the observer;

Fig. 2 is a perspective view of the blank of Fig. 1 at the first stageof assembly;

Figs. 3, 4 and "5 illustrate, in perspective views, .successive stagesof the assembly;

Fig. 6 is a perspective view, on an enlarged.scale, of a folded boxcorner prior to completion of the lock;

Fig. '7 is a perspective view of the box corner of Fig. 6 aftercompletion of the lock;

Fig.- 8 is a perspective view of the erected box ready for filling; and

Fig.9 is a perspective view of the filled and closed box.

in the following description and in the claims, various structuraldetails will be identified by specific names for convenience. The names,however, are intended to be generic in their application. Correspondingreference characters refer to corresponding parts in the several figuresof the drawings.

in the drawings accompanying, and forming part of, this specification,certain specific disclosure of the invention is made for the purpose ofexplanation of'broader aspects of the invention, but it is understoodthat the details may be modified in various respects without departurefrom the principles of the invention and that the invention may beapplied to other structures than the one shown.

The blank A may be cut and scored, in multiple, from a large sheet orroll of paperboard or other suitablefoldable material on an automaticcutting and creasing ma chine.

The blank A is traversed by several scored fold lines to provide a mainor bottom panel 11 to which a front panel-12 and a back'panel 13 arearticulated along afront 3 fold line 14, and a back fold line 15,respectively. Side panels 16 and 17 are articulated to the bottom panel11 along side fold lines 18 and 19, respectively.

Lock flaps 26, 21, 22 and 23 are articulated to the front and backpanels along corner fold lines 24, 25, 26, and 27, respectively. Thesecorner fold lines are either aligned with, or slightly offset withrespect to, the side fold lines 18 and 19 to compensate for thethickness of the board and of the liner in a conventional manner. Cornerflaps 28, 29, 30 and 31 may be articulated to the side panels 16 and 17along corner flap fold lines 32, 3-3, 34 and 35, respectively.

A top panel 36 is articulated to the back panel along a cover fold line37. A front tuck flap 38 and side tuck flaps 39 and 48 are articulatedto the top panel 36 along tuck flap fold lines 41, 42 and 43,respectively.

The configuration of the tuck flaps 38, 3? and 4tl'is optional.

The illustrated configuration of the flaps is conventional in frozenfood boxes and comprises tab projec tions 44 and 45 fitting into cuts 46and 47 in the side panels 16 and 17, respectively. Similarly, the fronttuck flap 38 has a locking tab 48 fitting into a cut 49 in the frontpanel 12 and engages edge portions 50 and 51 of the cut withcorrespondingly oriented edge portions 52 and 53 of the tab 48. Thesecover locking details are in common use and do not form a part of thepresent invention.

The improved corner locks of the box blank comprise external cuts in theside wall panels and in the associated lock flaps. These cuts are movedinto interlocking engagement after erection of the front, back and sidepanels of the box into upright position in regard to the bottom panel.

In the illustrated embodiment the construction of all four box cornersis alike, and it will therefore be sulficient' to describe one of thefour external cuts 54, 55, 56

and 57 in the lock flaps 20, 21, 22 and 23, which are brought intoengagement with other external cuts 58, 59, 60 and 61 in the side panels16 and 17, respectively.

The external cut 55 is preferably of bent outline and comprises anexterior portion 62, an intermediate portion 63 extending at an angle toexterior portion 62, and an interior portion 64 extending at an angle tothe intermediate portion 63. The interior portion 64 runs preferably ina substantially radial direction towards the box corner marked by theintersection of the fold lines 14 and 19. p

The corresponding external cut 59 in the side panel 17 comprises aninterior portion 65 and an exterior portion 66. When the panels andflaps are in corner-forming position, as is also shown in Figure 6, theinterior portion 65 of the cut 59 is in register with the interiorportion 64 of the cut 55. This permits edges of the two cuts to bebrought into .edge-to-edge engagement, as will later be described. As isbest seen in Figure 6, the exterior portions of the two cuts are not inregister, but are offset. The amount of the offset is roughly equal tothe extent of the intermediate portion 63 of cut 55.

The offset is selected in accordance with the flexibility of the board.In the type of board more commonly used for frozen food packages, theoffset may be of the order of 55; of an inch, or roughly 2 /2 mm.

For, the purpose of locking, the corner assembly is flexed adjacent tothe external portions 62 and 66 into the position shown in Figure 7.This will be described in greater detail further below. At this point itwill suffice to say that the amount of offset should be such that theenga'ge-' ment shown in Figure 7 can be formed without perma-- nentlycreasing the board at the base of the tongue or projection 67 formed bythe angularly disposed cuts 62 and 63.

Internal cuts 68, 69, 70 and 71 of bent outline form internal tongues72, 73, 74 and 75 in the side panels 16 and 17. The internal tongues aredirected toward the re spective box corners and serve to anchor the lockflaps in flat side panel overlying position when the box is set up. Thiswill become apparent as the description proceeds.

Additional external cuts 76, 77, 7-8 and 79 may optionally be providedin the lock flaps 20, 21, 22 and 23. In the drawings, these cuts areshown by broken lines to indicate that the cuts are optional. Ifprovided, they are arranged in such a position that they are incoincidence with the upper portions 80, 81, 82'and 83 of the internalcuts 68, 69, 7t} and 71 when the corner is formed, In this position thecuts form a secondary or supplemental lock between the lock flaps andthe side panels. This lock engages by reason of the inherent stiffnessof the board. It is supplemental in that it assists, but is not dependedon, for maintaining the box corners locked. The primary lock is the oneformed by the cuts 54, 55, 56 and 57 together with the cuts 58, 59, and61. This lock is not brought into engagement by resiliency of the boardbut is positively formed by a mechanical locking action, as will laterappear.

The optional cuts 76, ,77, 78 and 79 are also preferably radiallydisposed with respect to the box corners and, for

the same reason, the upper portions 80, 81, 82 and 83 are likewisesubstantially radially disposed with respect to the box corners.

A sheet 84 of liquid impermeable liner material, for example, celluloseacetate, is adhesively secured to the blank A along glue areas marked ain Figure 1.

The glue areas are so selected that the liner follows the folding motionof certain panels and flaps to which it is attached, and does not followother flaps or blank portions to which it is not attached. The liner issubstantially rectangular in outline and corresponds roughly to the sizeof the box blank A, not including the front tuck flap 38.

The blank A together with its liner 84 may be transformed into hollowbox form either by hand, or preferably, by automatic box machinery asdisclosed in the co-pending application of Chester 1. Pierce, Jr. andThomas F. Burke, Serial No. 487,632, filed February 11, 1955. The'rnachine operations, which may also be carried out by hand, aresubstantially as follows:

The side panels 16 and 17 are first folded towards upright position withrespect to the bottom panel 11 along the side fold lines 18 and 19. Themarginal portions of the liner 84 which are adhesively secured to theside panel take part in this folding operation and cause a more or lessindefinite crease to be formed in line with the fold lines 26, 42 and27, 43 of the box blank. This is illustrated in Figure 3.

Figure 4 illustrates the side panel 16 and 17 in substantially uprightposition. At about this point, the front panel 12 and the back panel 13are folded about their respective fold lines 14 and 1S, andsubstantially simultaneously the lock flaps 2t), 21, 22 and 23 arefolded along their fold lines 24, 25, 26 and 27 to assume an angularposition with respect to the front panel 12 and the back panel 13.

Also, the corner flaps 28, 29, 30 and 31 are folded about theirrespective fold lines 32, 33, 34 and 35 to assume an angular positionwith respect to the side panels 16 and 17. Since the liner is adhesivelysecured to the corner flaps, the formation of corner gusset folds 85,86, 87 and 88 of the liner is thus initiated.

Figure 4 illustrates the blank shortly before folding of the cornerflaps 28, 29, 30 and 31 and Figure 5 illustrates the position of thecorner-forming flaps and panels :tion 65 of the cut 59 in the sidepanel.

edge of the cut 69. This engagement constitutes a supplemental lock formaintaining the corner assembly in erected position.

In the condition illustrated in Figure 6, the box corners are ready forengagement of the primary locks as follows:

A force F is exerted in the direction and at the point indicated by thearrow 92 at the tongue or projection 67 formed by the offset of the cut55. At the same time the side panel 17 is supported on the inside alongan area 3 between the corner 25 proper and the end of the cut 62. Thiscauses the tongue 67 to snap in back of the portion of the side panelwhich lies between the cut 66 and the fold line 33. The completed lockis shown in Figure 7. The lock proper is formed by the interior portion64 of the cut in the flap 21 and the interior por- This cut lies inregister with the cut portion 64, but is not visible in Figure 7.However, it was previously explained that the two locking cuts, namelythe cut 59 in the side panel and cut 55 in the lock flap are so laid outthat the lower portions lie in register when the corner is square, sothat, by flexing of the board, edges of the registering cuts can bebrought into edge-to-edge engagement. This engagement locks the corneragainst forces directed from the inside of the box outwardly.

The exterior portion of the cuts, namely the portion 62 of the cut 55and the portion 66 of the cut 59, per form the function of a safetycatch which keeps th edges of the lower portions of the cuts inengagement.

The box corner is resistant to forces acting from the outside towardsthe inside by reason of the edge-to-panel engagement between the sidepanel 17 and the front panel 12. More particularly, the side edge of thepanel 17 represented by the fold line 33 rests against the interiorpanel surface of the front panel 12 adjacent the corner fold line 25.

This mechanical tightness of the box corner against inwardly directedpressure is important for the packaging of frozen foods, since thefilled enclosed cartons are tightly overwrapped. Tight overwrappingnaturally tends to push the front and back panels 12 and 13 towards theinside of the box. The corner construction prevents this from happening.

In addition to being mechanically tight, the carton is fluidtightbecause of the formation of gussets at all four box corners, the gusset86 being visible in Figures 6 and 7.

The locked carton is shown in Figure 8. it is ready for filling withmerchandise and may then be closed in conventional manner by equallyconventional closing machines. Figure 9 shows the closed carton incondition for overwrapping.

From the hereinbefore described locking procedure, and more particularlyfrom Figures 6 and 7, it is seen that the application of forces forlocking the box corners will not interfere with, nor damage, the liner34. it is evident that no projectable elements of a plunger or mandrelinside the box are required for performing the locking operation, butthat the locking operation can be performed by a force applied from theoutside and support from the inside. This makes the box structureideally suited for handling by high speed automatic machinery of theplunger and die type.

What is claimed is:

l. A lined folding box, particularly for the packaging of frozen foods,consisting of a box blank and a liner, said box blank comprising, abottompanel; a front panel and a back panel articulated to the bottompanel 'alonga front fold line and a back fold line, respectively;sidepanels articulated to the bottom panel along side fold lines; cornerflaps articulated to the ends of theside panels along corner flap foldlines; lock flaps articulated to the ends of the front and thebackpanels along lock fiap fold lines which are substantially in coincidencewith said corner fold lines, considering the set up box, said sidepanels having internal cuts in them forming internal tongues in the sidepanels directed towards the box corners, the tips of the tongues beingat a distance from the lock flap fold line less than the length of therespective .lock flap so that the tongues overlie said lock flap,considering the box in set up condition, said liner overlying saidbottom panel, said front and back panels, said side panels, said lockflaps and said corner flaps, considering the blank and the liner in flatcondition, said box being provided with interlocks between said lockflaps and said side panels, each interlock including an external cutextending into the body of the side panel from its top edge and anexternal cut extending into the body of the lock flap from its top edge,said two external cuts having an interior portion remote from therespective top edge and an exterior portion adjacent the top edge, theinterior portions of both cuts being in substantial coincidence when thebox is set up, for engagement of edges of the interior portions theexterior portion of the side wall cut being at a greater distance fromthe respective flap fold line than the exterior portion of the lock flapcut, the exterior portion of the lock flap out being in angularrelationship to the interior portion of the lock flap cut, therebyforming a hook on the lock flap pointing towards the flap fold line, thehook being sufficiently short to permit flexing of the stock withoutpermanent creasing by pressure applied adjacent the hook and directedtoward the inside of the box to snap the hook from a position overlyingthe end panel into a position underlying the end panel, whereby the faredge of the interior portion of the flap cut is flexed into engagementwith the near edge of the interior portion of the side panel cut.

2. A lined folding box, particularly for the packaging of frozen foods,consisting of a box blank and a liner, said box blank comprising, abottom panel; a front panel and a back panel articulated to the'bottompanel along a front fold line and a back fold line, respectively; sidepanels articulated to the bottom panel along side fold lines; cornerflaps articulated to the ends of the side panels along corner flap foldlines; lock flaps articulated to the ends of the front and the backpanels along lock flap fold lines which are substantially in line withsaid corner fold lines, considering the set up box, said side panelshaving internal cuts in them forming internal tongues in the side panelsdirected towards the box corners, the tips of the tongues being at adistance from the lock flap fold line less than the length of therespective lock .flap so that the tongues overlie said lock flap,considering the box in set up condition, said liner overlying saidbottom panel, said front and back panels, said side panels, said lockflaps and said corner flaps, considering the blank and the liner in flatcondition, said box being provided with interlocks between said lockflaps and said side panels, each interlock including an external cutextending into the body of the side panel from its top edge and anexternal cut extending into the body of the lock flap from its top edge,said two external cuts having an interior substantially straight portionremote from the respective top edge, and an exterior portion adjacentthe top edge, the interior portions of both cuts being in register whenthe box is set up, the

exterior port-ion of the side wall out being at a greater distance fromthe respective flap fold line than the exterior portion of the lock flapcut, the exterior portion of 7 the lock flap out being in angularrelationship to the interior portion of the lock flap. cut, therebyforming a hook on the lock flap pointing towards the flap fold line, thehook being sufficiently short to permit flexing of the stock withoutpermanent creasing by pressure applied adjacent the hook and directedtoward the inside of the box to snap the hook from a position overlyingthe end panel into a position underlying'the end panel, whereby the faredge -,of the interior portion of the'flap cut is flexed into engagementwith the near edge of the interior portion of the side panel cut.

3. A corner construction for a folding box composed of a box blank and aliner blank overlying, and attached to, the inside surface of the boxblank, the box corner comprising a main panel; a first wall panelarticulated to said main panel along a first panel fold line; a secondwall panel articulated to said main panel along a second panel fold lineintersecting said first panel fold line at a corner angle; a corner flaparticulated to said second panel along a corner flap fold line; a lockflap articulated to said first wall panel along a flap fold line lyingsubstantially in coincidence with said corner flap fold line,considering the corner in set up condition; said second Wall panelhaving an internal cut in it forming an internal tongue in said secondpanel directed towards, and overlapping, said lock flap, considering thecorner in assembled position, the tip of the tongue being closer to saidlock flap fold line than the length of the lock flap to provide suchoverlapping, said first and said second wall panels and said lock flaphaving a top edge substantially parallel to said main panel, consideringthe corner in assembled condition, said corner flap underlying saidfirst wall panel with the liner folded around the corner flap to form agusset, said lock flap having a first external cut extending into itfrom its top edge, said second wall panel having a second external cutextending into it from its top edge, each of said external [cutscomprising an exterior portion adjacent the respective top edge and aninterior portion remote from the top edge, the interior portion of bothexternal cuts being in coincidence in the assembled corner, the exteriorportion of the said first cut extending at an angle with respect to theinterior portion, which interior portion is substantially radial withrespect to the point of intersection between said first and saidsecond'panel fold lines, the exterior portion of the said first cutmeeting the top edge of the lock flap at a point closer to said lockflap fold line than the distance from the corner flap fold line to thepoint of entry of said second cut into the top edge of the second wallpanel measured from the corner flap fold line, the top portion of thelock flap on the far side of the first cut forming a hook tip capable ofbeing resiliently displaced by pressure directed towards the inside ofthe box from a position overlying said second Wall panel into a positionunderlying the near top portion of the second wall panel in theassembled corner, in which position the interior portions of the twocuts are in edge to-edge engagement.

4. A cornerconstruction for a folding box composed of a box blank and aliner blank overlying, and attached to, the inside surface of the boxblank, the box corner comprising, a main panel; a first wall panelarticulated to said main panel along a first panel fold line; a secondwall panel articulated to said main panel along a second panel fold lineintersecting said first panel fold line at right angles; a corner flaparticulated to said second panel along a corner fold line; a lock flaparticulated to said first wall panel alonga flap fold line lyingsubstantially in coincidence with said corner fold line, considering theset up corner; said second wall panel having an internal cut in itforming an internal tongue in said second panel overlapping said lockflap, considering the corner in assembled condition, said first and saidsecond Wall panels and said lock flap having a top edge substantiallyparallel to said main panel, considering the corner in assembledcondition, said corner flap underlying said first wall panel with theliner folded about the corner flap to form a gusset, said lock flaphaving a first external cut extending into it from its top edge, saidsecond wall panel having a second external cut extending into it fromits top edge, each of said external cuts comprising an exterior portionadjacent the respective top edge and an interior portion remote from thetop edge, the interior portions of both external cuts being incoincidence in the assembled corner, the exterior portion of said secondout being at a greater distance from the corner fold line than thedistance of the exterior portion of the first cut from said flap foldline, the exterior portion of at least one of said external cuts beingat an angle to the interior portion of the same cut, whereby a hook isformed by the angled exterior cut portion adjacent the respective topedge, the top portion of the lock flap on the far side of the first cutbeing flexible by pressure exerted at the top edge from positionoverlying said second Wall panel into a position underlying the near topportion of the second wall panel in the assembled corner, in whichposition the interior portions of the two cuts are in edge-toedgeengagement.

5. A corner construction for a folding box, particularly for use with aliner blank overlying, and attached to, the inside surface of the boxblank, the box corner comprising a main box panel; a first wall panelarticulated to said main panel along a first panel fold line; a secondwall panel articulated to said main panel along a second panel fold lineintersecting said first panel fold line at a corner angle; a corner flaparticulated to said second panel along a corner flap fold line; a lockflap articulated to said first Wall panel along a flap fold line lyingsubstantially in coinci ence with said corner flap fold line,considering the corner in set-up condition; said second wall panelhaving an internal cut in itforming an internal tongue in said secondpanel directed towards, and overlapping, said lock flap, considering thecorner in assembled condition, the tip of the tongne being closer tosaid lock flap fold line the length of the lock flap to provide suchoverlapping, said first and said second wall panels and said lock flaphaving a top edge substantially parallel to said main panel, consideringthe corner in assembled condition, said corner flap underlying saidfirst wall panel, said lock flap and said second wall panel beingprovided with an interlock including a first external cut and a secondexternal cut, one of said cuts extending into the lock flap from its topedge, the other external cut extending into said second wall panel fromits top edge, each of said external cuts comprising an exterior portionadjacent the respective top edge an interior portion remote from the topedge, the interior portions of both external cuts being in coincidencein the assembled corner, the exterior portions of said first out beingoffset with respect to the interior portion of said first cut, theexterior portion of the external cut meeting the top edge of the lockflap at a point closer to the lock flap fold line than the distance fromthe corner flap fold line to the point of entry of the cut into the topedge of the second wall panel measured from the corner flap fold line,the top portion of the blank stock adjacent the otiset portion forming ahook tip capable of being resiliently displaced by pressure directedagainst the second wall panel and the overlying lock flap past theexterior portion of the other end into locking position, in whichposition the interior portions of the two cuts are in lockingengagement.

References Cited in the file of this patent UNiTED STATES PATENTS1,515,983 Williams Nov. 18, 1924 1,517,528 Elackman Dec. 2, 19242,503,798 Buttery Apr. 11, 1950 2,605,955 Meller Aug. 5, 1952 2,675,164Haas Apr. 13, 1954 FOREIGN PATENTS 17,304 Norway Ian. 27, 1908

